16,17-acetal derivatives of the retro pregnane series



United States Patent 3,523,943 16,17-ACETAL DERIVATIVES OF THE RETRO PREGNANE SERIES Engbert Harmen Reerink, Pieter Westerhof, and Hendrik Frederik Louis Scholer, Van Houtenlaan, Weesp, Netherlands, assignors, by mesne assignments, to US. Philips Corporation, a corporation of Delaware No Drawing. Continuation of application Ser. No. 681,939, Nov. 9, 1967, which is a continuation of application Ser. No. 472,702, July 16, 1965. This application Apr. 14, 1969, Ser. No. 824,341

Int. Cl. C07c 173/00, 169/66; A61k 17/06 US. Cl. 260-23955 14 Claims ABSTRACT OF THE DISCLOSURE 16u,17o-diOXy derivatives of 9 3,100; steroids of the pregnane series. Examples are 6-fluora-16a, 17ot-isopropylidenedioxy-9,B, IOu-pregna 4,6 diene 3,20 dione; 6-methyl, 16a,17a-isopropylidenedioxy-9fl, wot-pregna- 4,6-diene 3,20 dione and 16a,17u-isopropylidenedioxy- 9,8, a-pregn-4-ene-3,20-dione. The compounds are generally progestationally active. This abstract is not intended to be a description of the invention defined by the claims.

This application is a continuation of application Ser. No. 681,939, filed Nov. 9, 1967, and now abandoned, said application Ser. No. 681,939 being a continuation of application Ser. No. 472,702, filed July 16, 1965, and now abandoned and said application Ser. No. 472,702 being a continuation-in-part of application Ser. No. 201,824, filed June 12, 1962, and now US. Pat. 3,198,782.

The invention relates to new 9,6,l0a-steroids having the general formula:

CHzRZl i "0 X2 Ha I in which formula:

R is a 3-keto-4-dehydro-, 3-keto-4,6-bisdehydro-, 3-keto- 1,4-bisdehydro-, 3-alkoxy-3,5-bisdehydroor 3-acyloxy- 3,5-bisdehydro-group,

R is a hydrogen atom, fluorine atom, chlorine atom, bromine atom or a methyl group, R is a hydrogen atom or a hydroxy or acyloxy group, X, is a hydrogen atom or an alkyl, aryl, aralkyl or heterocyclyl group,

X is a hydrogen atom or an alkyl, aryl, aralkyl or heterocyclyl group,

with the exception of the combination R is an acyloxy- 3,5-bisdehydro-group and R is fluorine, chlorine or bromine.

If R represents a 3-alkoxy-3,5-bisdehydro group the alkoxy group preferably is an aliphatic or mixed aliphaticaromatic or an alicyclic alkoxy group containing from 1 to 10 carbon atoms, for example, a methoxy, ethoxy, propoxy, tert. butoxy, cyclopentyloxy, cyclohexyloxy or benzyloxy group.

If R is an acyloxy group, then this group preferably is the acyloxy group of an aliphatic monocarboxylic acid containing from 1 to 6 carbon atoms, for example, formic acid, acetic acid, propionic acid or butyric acid.

It R represents an acyloxy group, this group prefer- 3,523,943 Patented Aug. 11, 1970 ably is the acyloxy group of an aliphatic mono-, dior tricarboxylic acid containing from 1 to 20 carbon atoms, or the acyloxy group of a mixed aliphatic-aromatic carboxylic acid. Examples of such acyloxy groups are: formoxy, acetoxy, propionoxy, butyroxy and the acyloxy groups of malonic acid, succinic acid, citric acid, stearic acid, palmitic acid.

It should be remarked that the stereochemical configuration of the steroid skeleton of the compounds according to the invention at the carbon atoms 8, 9, 10, 13 and 14 is the same as that in dihydroisolumisterone. Castells et al. (Proc. Chem. Soc. 1958, page 7) have shown that the latter compound has the configuration 85,9,8,10a,13/3,14a. The compounds according to the invention are designated as 913,10oz-St610id8 to indicate at which carbon atoms (9 and 10) the stereoconfiguration differs from that of the normal steroids and in which sense (913,10ain contrast with the 9a,l0 3-configuration of the normal steroids).

The compounds according to the invention have a particular pharmacological activity. More particularly they have a hormonal activity. Generally the compounds are progestational. Especially l6u,l7a-isopropylidenedioxy 9 3,10a-pregn-4-ene-3,20-dione is orally and parenteral progestational, not androgenic, not estrogenic, inducing deciduomata, maintaining pregnancy, especially when an estrogenicaly active compound is administered simultaneously, and inhibiting ovultion. The compound 16a,l7ozisopropylidenedioxy-9 3,10a-pregna-4-diene 3,20 dione qualitatively has the same properties as the preceding compound. Furthermore, both 9B,10a-pregna-4,6-diene 16a,17a-isopropylidenedioxy-9 S,10a-pregn-4-ene- 3,20-dione 16a,17a-isopropylidenedioxy-9B,10u-pregna- 4,6-diene-3,20-dione 9,6,10a-pregna-4,6-diene-3,20-dione-[16u,17a-d]- 2'a-pheny1-2'B-methyl-1',3-dioxolane 6a-methyl-16a,17a-isopropylidenedioxy-913,10a-

pregn-4-ene-3,20-dione QB-methyl-16a,17m-isopropylidenedioxy-9fl,10a-

pregn-4-ene-3,20-dione 3-acetoxy-16a,l7u-isopropylidenedioxy-9B,10a-

pregna-3,5-diene-20-one 6-Chl01'O-16u,17 a-isopropylidenedioxy-9p,IOa-pregna- 1,4,6-triene-3,20-dione 6-fluoro-1 6a, 17 a-isopropylidenedioxy-9 8,1 Oct-pregna- 4,6-diene-3,20-dione 1 6a, 17a-isopropylidenedioxy-9 18, l0u-pregnal ,4,6-

triene-3,20-dione 6-Ch1OI'0-16a,17 a-isopropylidenedioxy-9B,10ozpregna-4,6-diene-3,20-dione 2l-acetoxy-l6a,l7a-isopropylidenedioxy-9fi,10a-

pregna-4,6-diene-3,20-dione 21-aC6tOXy-16a,l7 u-isopropy1idenedioxy-9p,10a-

pregn-4-ene-3,20-dione 6fl-fiuoro-16u,17a-isopropylidenedioxy-9 8,l ma-pregna- 1,4-diene-3,20-dione 6-methyl-16a,17a-isopropylidenedioxy-9B,10a-

pregna-4,6-diene-3,20-dione 16a,17oz-isopropy1idenedioxy-913,IOu-pregna-IA- diene-3,20dione 6 3-chloro-16a,17a-isopropylidenedioxy-9B,10a-

pregna-1,4-diene-3,20-dione (a) A compound of the formula:

011F321 o= (H8 OH 5 T011 I i I I H R I Ru in which formula R R and R have the meanings given to them in claim 1, with the understanding that R cannot be a 3-acy1oxyor 3-alkoxy-3,5-bisdehydro group, is treated with a ketone or aldehyde of the formula X1 (H1Xz o in which formula X and X are a hydrogen atom, an alkyl, aryl, aralkyl or a heterocyclyl group and may be equal or different groups;

(b) A compound of the general formula:

in which formula R R21, X and X have the abovementioned meanings, whilst a double bond may be present between the carbon atoms 6,7, is treated with 8e0 2,3- dichloro-5,6-dicyano-benzoquinone in order to introduce a double bond between the carbon atoms 1 and 2;

(c) A compound of the general formula:

CHz-Rn i O Xs I l in which formula R 21, X and X have the abovementioned meanings, is treated with a benzoquinone, in which 2 or more of the hydrogen atoms are substituted by chlorine or by chlorine and a cyano group, for ex- 4 ample, 2,3-dichloro-5,6-dicyano-benzoquinone, or 2,3-5,6- tetrachloro-benzoquinone (chloranil) for the introduction of a double bond between the carbon atoms 6 and 7;

(d) A compound of the general formula:

tllHz-Rzi 0:0

in which formula OR is an alkoxy or an acyloxy group and R R X and X have the above-mentioned meanings, is treated with an oxidizing agent, such as manganese dioxide, 2,3 dichloro-S,6-dicyanobenzoquinone (D.D.Q.) tertiary butyl-chromate, so that the corresponding 3- keto-4,6-bisdehydro compound is produced;

(e) A compound of the general formula:

in which compounds R R21, X and X have the abovementioned meanings, is converted into a 3-alkoxy-3,5-bisdehydro compound by reaction with an orthoformic acid alkyl ester in the presence of a catalyst, such as paratoluene-sulphonic acid or hydrochloric acid,

(f) A compound of the general formula:

(KHz-R21 a in which formula R R X and X have the abovementioned meanings, is treated with a dialkoxypropaue in the presence of a catalyst, for example p-toluenesulphonic acid, to produce the corresponding 3-alkoxy-3,5- bisdehydro compound; (g) A compound of the general formula:

in which formula R is a hydrogen atom or a methyl group and R X and X have the meanings given in claim 1, is treated with an esterifying agent, such as acyl anhydride or isopropanyl acylate, in the presence of a catalyst, such as p-toluene sulphonic acid, to produce the corresponding 3-acyloxy-3,5-bisdehydro compound; (h) A compound of the general formula:

CHr-Rzr in which formula RO represents an alkoxy or an acyloxy group and R X1 and X have the abovementioned meanings, is halogenated with perchloryl fluoride or with an N-haloimide, such as as N-bromoor N-chloro-succinimide, or with chlorine or bromine, to produce the corresponding 3-keto-4-dehydro-6-fluoro (or 6-chloroor 6-bromo) compound,

(j) A compound of the general formula:

CHr-Rzr om CH3 i a t X2 I ll ')n in which formula R is a hydrogen, chlorine or bromine atom 11 is 2 and R X and X have the above-mentioned meanings, is hydrogenated with hydrogen in the presence of a noble metal catalyst on a support, in which reaction the 6-di-R-methylene group is converted into a 6-methyl group; (k) A compound of the general formula:

CH2-R21 on 1 x in which formula R2 X and X have the above-mentioned means, is isomerized with an acid, such as bydrochloric acid, in an organic solvent, such as acetic in which formula:

R is a 3-keto-4-dehydro, 3-keto-4,6-bisdehydroor 3- keto-1,4,6-trisdehydro-group,

R is a hydrogen atom or a methyl group and X and X have the 'above-mentioned means, is subjected to acylolysis by treatment with an alkali acylate, as the case may be, with subsequent saponification of the 2l-acyloxy group formed.

The reactions may be carried out in a manner familiar to the normal expert in this field of chemistry. In general, the reactions are carried out in the presence of solvents at temperatures between -20 C. and about C., while it is preferable for many reactions to take place in an atmophere of an inert gas, for example, nitrogen.

Many of the afore-mentioned groups of starting materials have not been described in the literature before. Brief directions for preparing these compounds are given below (the paragraph reference characters (a) to (1) correspond to those above).

(a) 16oc,l7ot-dlhYdIOXY-9B, 10a-steroids may be prepared by microbiologically hydroxylating a 20-keto9/3,- wot-steroid having an a-hydrogen atom at the position 17 and two hydrogen atoms at the carbon atom 16, for example, with the aid of Sepedom'um ampullosoporum Damon, Sepedonium chrysospermum (Bull, Fr. Bo udyn) or Stagonospora curtesii (Berk et Cke.) Sacc, after which an tx-hydroxyl group is introduced at the carbon atom 16, by subsequently splitting off water from the compound produced, for example, with the aid of dilute sodium hydroxide or of sulphuric acid with the resultant formation of a 20keto-16-dehydro-9(3,lOa-steroid, and by treating such a compound with osmium tetraoxide with subsequent decomposition of the intermediate osmate with hydrogen sulphide, or by hydroxylating such a 16-dehydro compound with potassium permanganate under conditions which are neutral or mildly acid due to the presence of formic acid.

If the desired final product contains a 1- and 6-dehydro double bond, a 6-halogen atom or a 2l-acyloxy or 21- hydroxy group, the 16,17-ketalising reaction and the preceding introduction of a 16- and 17-hydroxyl group preferably are performed before the introduction of the said double bonds and/or substituents. In general, the 16,17-ketals according to the invention are comparatively stable compounds, and this stability may be utilized to advantage when further substituents have to be introduced in these compounds.

The ketalizing reaction itself is preferably performed in the presence of a catalyst, such as hydrochloric acid, boron trifiuoride or perchloric acid. As an aldehyde or ketone use is preferably made of a compound in which both X and X are either alkyl groups containing from 1 to 6 carbon atoms or hydrogen atoms, or in which one is a hydrogen atom and the other an alkyl group containing from 1 to 6 carbon atoms, for example, formaldehyde, acetaldehyde or acetone. Good results are also achieved with acetophenone and with acetofuran.

(e) The enol-etherification proceeds particularly successfully with orthoformic acid alkyl ester, the alkyl part of which is an aliphatic group containing from 1 to 6 carbon atoms, for example, methyl or ethyl.

(g) The reaction is preferably carried out with isopropenyl acetate or with acetic acid anhydride. It should be noted that enol-esterification of a 6-halogen-9p,l0a-steroid by means of the method used did not produce the desired result.

(1') The starting materials for this reaction are divided into two different groups, i.e., the 6-dihalo-methylene compounds and the 6-methylene compounds, each group requiring a special method of production.

The production of the 6-dihalo-methylene compounds may start from a 3-ethoxy-3,5-bisdehydro-9/3,lOct-steroid, which in the presence of an organic base, for example, collidine or pyridine, is reacted with a tetrahalomethane, for example, tetrabromomethane or trichloromonobromomethane, if required in the presence of a peroxide, such as benzol peroxide, or with irradiation with ultraviolet light. During this reaction a 3-keto-4-dehydro-6-dihalomethyl compound is formed. This compound is dehydrohalogenated in the usual manner with a base in an aliphatic alcohol to produce the desired starting material (6-dihalo-rnethylene) The 6-methylene compounds may be prepared by the Vilsrneier-reaction. For this purpose, for example, 3- ethoxy-3,5-bisdehydro-9fi,mot-steroid is reacted with dimethylformamide and phosgene. By hydrolysis of the intermediate iminium compound the corresponding 3-ethoxy-3,S-bisdehydro-6-formyl-9fi,wot-steroid is produced. This compound can be converted into the corresponding 6-hydroxy-methyl-3-ethoxy-3,5-bisdehydro compound by catalytic reduction or by reduction with sodiumor lithiumborohydride. Subsequent treatment of the latter compound with aqueous dilute acids gives rise to hydrolysis of the enolether group with simultaneous dehydration of the 6-hydroxy-methyl group with the formation of a 3-keto-4-dehydro-6-methylene-9fl,l-0ot-steroid. The latter part of the reaction is preferably performed in dilute aqueous acetic acid or in dilute methanolic or ethanolic hydrogen chloride or sulphuric acid.

The hydrogenation of the -6-dihalomethylene group can suitably be carried out with a catalyst consisting of palladium deposited on strontium carbonate, in the presence of an organic base, such as tertiary amine, for example, triethylamine. The hydrogenation as a rule leads to the formation of a product consisting in excess of the 6amethyl compound. This compound may be converted into the 6/3-methyl compound by acid isomerisation.

(l) The production of 2l-iodo-2O-keto-9f3,IDOL-steroids may be effected as follows:

A 9,8,10a-steroid having an acetyl group in B-position at the carbon atom 17 is subjected to a condensation reaction with an oxalic acid dialkyl ester, for example, the dimethyl or diethyl ester, in the presence of a base, such as sodium hydride or sodium methylate. Treatment of the resulting condensation product with iodine gives the desired 2l-iodo-20-keto-9fi,IDOL-steroid to be used as the starting material for the acylolysis reaction.

The compounds according to the invention may be worked up into pharmaceutical or veterinary preparations in a conventional manner. Injection liquids are prepared by dissolving a compound according to the invention in methylene chloride, dissolving the resulting solution in arachid oil and subsequently removing the methylene chloride by evaporation. Suppositories may be prepared by intimately mixing an active compound with an ester of a higher aliphatic alcohol and a higher aliphatic carboxylic acid, for example carbowaxes or cacao butter, or with a mixture of gelatine and glycerol. The compounds according to the invention may further be worked up into tablets with the usual fillers, such as starch, or binding agents or lubricants, for example, magnesium stearate, carboxy-methyl cellulose and the like.

EXAMPLES (1) Production of 9,9,10a-pregna-4,16-diene-3,20-dione from 16a-hydroxy-9B,10a-pregn-4-ene-3,20-dione gms. of 16a-hydroxy-9f3,10u-pregn-4-ene-3,20-dione were dissolved in 500 mls. of benzene. After the addition of 100 mgms. of p-toluenesulphonic acid the solution was refluxed for 1 hour. The solvent was then distilled off in vacuuo and the residue was absorbed in methylene chloride. After washing with sodium bicarbonate and water and drying, the substance was evaporated to dryness and the residue (4.9 gms.) subjected to chromatography on silica gel. 3.8 gms. of a pure fraction were obtained which,

8 after crystallisation from methanol, had a melting point from 165 C. to 167 C. The infrared absorption spectrum included the following bands: 1663, 1616, 1579, 1368, 1233, 947, 862 and 324 cmr E r max. 240 25,300.

(2) Production of 16a,17a-dihydroxy-9fi,10a-pregn-4- one-3,20-dione from 9/3,10a-pregna-4,16diene-3,2=0dione Solution A.-l0 gms. of 9,6,10ot-pregna-4,16-diene-3,20- dione were dissolved in 250 mls. of acetone, and 23 mils. of formic acid (10%) are added to this solution.

Solution B.-6.3 gms. of potassium permanganate were dissolved in mls. of water, mls. of acetone being then added to the solution. The solution A was poured into a calibrated separating funnel and the solution B was poured into a second calibrated separating funnel. The two separating funnels were connected by small lengths of rubber hose to 2 glass coils which were both connected to the same Y-piece. The third tube of the Y-piece was also connected to a glass coil. The assembly of glass coils and Y-piece was arranged in a vessel so that the reaction system could be cooled in carbon dioxide-acetone. The two solutions A and B were caused to flow together at a rate such that the overall contact time was about 10 seconds. The reaction temperature was adjusted to about -5 C. The reaction mixture was poured into a stirred sodium bisulfite solution (40 mls., 10%) to which a small amount of manganese sulphate had been added. After the manganese dioxide formed had been removed by filtering and thoroughly washed with acetone, the acetone was distilled off from the filtrate in vacuo. The resulting crystallisate was drawn off, washed with water and dried. Yield: 80% of substantially pure 16u,17a-dihydroxy-9,8, 10oz-pregn-4-ene-3,ZO-dione. An analytically pure preparation exhibited the following physical constants: melting point 209212 C.; 6 241.5 mm.-= 16,600; [a] -13t13; LR. 860, 1231, 1348, 1415, 1615, 1661 and 1693 cm.

(3) Production of 16a,17a-isopropylidenedioxy-9fi,10a-

pregn-4-ene-3,20-dione from 160:,17oc-dihYdIOXY-9B, 10a-pregn-4-ene-3,20-dione 13.85 gms. of 1604,1704 dihydroxy 9fl,l0a-pregn-4- ene-3,20-dione were suspended in 400 mls. of acetone. 4 mls. of perchloric acid (70%) were added dropwise under a nitrogen atmosphere at room temperature. Owing to the conversion to the 16,17-ketal the reaction mixture became clear after a few minutes. The mixture was stirred for 45 minutes and the solution was poured into 2 ls. of water. After extraction with ether and washing of the extract the solvent was removed. crystallisation from ether produced 160:,17u isopropylidene-dioxy 9,8,10apregn-4-ene-3,20-dione in a yield of 89%, melting point ISO-151 C.; e 241 mms.=16,600; 13R. 859, 103-8, 1211, 1343, 1374, 1382, 1421, 1608, 1666 and 1712 cm.-

(4) 5 gms. of 1606,170L isopropylidenedioxy-9/3,10apregn-4-ene-3,20-dione were dissolved in chloroform and the solution was homogeneously mixed with the gms. of lactose. The mixture was dried at 40 C. for 1 hour. It was then wetted with a 10% aqueous solution of 1.5 gms. of gelatine and subsequently ground through a 20- mesh sieve. The mixture was dried at 45 C. for 24 hours and again ground through a 20-mesh sieve. The grains were weighed. Proportional amounts of potato starch, Talcum venetum and magnesium stearate were then added in quantities of optimally 33.5, 8, and 2 gms. respectively. The resulting mixture was homogenized and worked up into tablets of 235 mgms. each.

(5) 0.2 mole of 16a-hydroxy-9fi,10a-pregna-4,6-diene- 3,20-dione was boiled for 3 hours under azeotropic distillation in benzene, to which 6 gms. of p-toluenesulphonic acid had been added. The resulting 9fl,10a-pregna-4,6,16- triene-3,20-dione, after recrystallisation from a mixture of equal parts of methylene chloride and diethylether, had a 9 melting point of 132.5-133 C. [a] =-430i'5 (dioxan); e (A max. 237.5)=l2,000; e ()t max. 284): 27,400.

18.15 gms. of this compound were dissolved in 300 mls. of benzene, after which 37.5 gms. of pyridine and 15 gms. of osmium tetraoxide in 500 mls. of benzene were added. The mixture was stirred in the dark at room temperature for three days. Ethyl acetate was added to the reaction product and the mixture was then treated with gaseous hydrogen sulphide, the reaction product of the steroid with osmium tetraoxide being decomposed. The resulting osmium sulphide was filtered oh and the remaining mixture of 918,10a-steroids was subjected to chromatography on silica gel. From the benzene ethyl acetate (1:1) fraction 160:,17u dihydroxy 9,8,10m-pregna-4,6-diene-3,20- dione was isolated. Melting point 210-215 C. (after recrystallisation from methylene chloride and diisopropyl ether). [a] =528i5; e (A max. 2 85)=27,100.

The resulting compound was converted, with acetone and 70% perchloric acid as a catalyst, into 160a, 17ot-isopropylidene dioxy 9,8,10u pregna-4,6-diene-3,20-dione. The substance, when crystallized from a mixture of methylene chloride and diisopropyl-ether, had a melting point of 182-183 C.; [a] =452:':5 (dioxan); 60. max. 284) =27,100.

(6) 16u,17u isopropylidenedioxy 9 8,100: pregn 4- ene-3,20-dione was converted in benzene, with isopropenyl acetate and p-toluenesulphonic acid as a catalyst, into 3 acetoxy 160:,170; isopropylidenedioxy-9;3,10ut-pregna- 3,5-diene-20-one. The compound was recrystallized from methanol to which a trace of pyridine had been added. Melting point 108-112" 0.; e0. max. 234) =18,200.

In an atmosphere of nitrogen 689 mg. (2 mmoles) of 16a,17a. dihydroXy 9 3,10a-pregna-4,6-diene -3,20-dione were suspended in 50 ml. of freshly distilled acetophenone. To the magnetically stirred suspension was added 0.3 m1. of 70% perchloric acid.

The steroid went into solutionwithin 15 minutes and was allowed to stand at room temperature overnight. The reaction mixture was filtered through silica gel (400-fold in respect to the steroid). Most of the acetophenone was eluted with petroleumether and benzene, while the steroid, along with some acetophenone, was eluted with ethylacetate. The residual acetophenone was removed in high vacuo and the 913,10a-pregna-4,6-diene-3,20-diono-[16st, 17a d] 2'13 methyl-Z'a-phenyl-l',3'-dioxolane was obtained in pure form by recrystallization from benzene/ ligroin and finally from diisopropylether, melting point 190-191; [oc] =5O7i5 (dioxan);

UV: AZ =2845 m /e=25,600

IR- and NMR-spectra are consistent with the structure.

(A) A suspension of 1.034 g. (3 mmoles) of 16a,17adihydroxy-9B,10a-pregna-4,6-diene-3,20-dione in g. of freshly distilled Z-furylmethylketone, 6 ml. of chloroform and 0.5 ml. of 70% perchloric acid was stirred in an atmosphere of nitrogen. After 35 minutes all steroid was in solution. After 2 hours 2 ml. of a saturated solution of potassium carbonate was added and the mixture was reduced to a slurry in high vacuo (bath temperature 35- 40 The residue was taken up in ether/methylenechloride 4:1 and consecutively washed with water (once), a solution of 2% sodiumbicarbonate (twice) and water (twice). The organic phase was dried over sodiumsulfate and evaporated to dryness in vacuo. The residue was dissolved in benzene and added to a column of silica gel (10-fold).

With benzene and isooctane/ethylacetate 5:1 some residual Z-furylmethylketone was eluted. Isoocetane/ethylacetate 3:1 eluted a mixture of the ketals II and III (ratio IIzIII ca. 4:1 as judged by NMR), melting point 183 186. The 95,1011 pregna 4,6 diene-3,20-diono-[16u, 1'7a-d]-2'a-methyl-2,B-(2"-furyl)-1,3'-di0xolane (II) was obtained pure by crystallization from methylenechloride/ ether, melting point 245-247; [a] =-426-i-5 (dioxane);

IR- and NMR-spectra are consistent with the structure.

(B) A suspension of 1.034 g. (3 mmoles) of 16ot,17udihydroxy-9,B,10ot-pregna-4,6-diene-3,20-dione (I) in 5 ml. of benzene, 11.0 g. Z-furylmethylketone and 0.05 ml. of 70% perchloric acid was stirred in an atmosphere of nitrogen. After 45 minutes all steroid was in solution. The reaction mixture was allowed to stand for 2 hours at room temperature. Ether/methylenechloride 4:1 (500 ml.) was added. The organic phase was extracted with a solution of 2% sodiumbicarbonate (thrice) and Water (thrice), dried over sodium-sulfate and evaporated under reduced pressure. The excess of 2-furylmethylketone was removed in high vacuo. The steroid was dissolved in benzene and chromatographed on silicagel (10-fold). The ketal III, the main product, was eluted with isooctane/ethyl-acetate 5: 1, 4:1 and 3:1, a small amount of a mixture of the ketals II and III was obtained with isooctane/ethylacetate 3:1 and 1:1 while some unreacted diol I was eluted with ethylacetate. The ketal 111 was recrystallized from methylenechloride/diisopropylether and pure 9 S,10u-pregna-4,6-diene 3,20 diono-[16a,17a-d]-2-fl-methyl-2u-(2-fu1yl)- 1',3'-dioxolane (III) was obtained, melting point 197- 198; [u] =474i5 (dioxane);

UV: AE2F=2841 m /e=26,200

IR- and NMR-spectra are consistent with the structure.

(9) 16a, 17a-isopropylidenedioxy-9p, 10ccpregna-l,4-diene-3,20-dione (A) A solution of 386 mg. (l mmole) of l6a,l7ozisopropylidene dioxy 913,100: pregn 4 ene-3,20-dione in 5 ml. of purified dry dioxane, containing 1% o. of hydrochloric acid, was treated in an atmosphere of nitrogen dropwise with a solution of 295 mg. (1.3 mmoles) of 2,3-dichloro-5,6-dicyano-benzoquinone in 10 m1. of dioxane, containing 1% 0. of hydrochloric acid. The reaction mixture was stirred at room temperature for 24 hours, treated with an excess of sodiumbicarbonate and a trace of water and refluxed for a period of 3 minutes. The mixture was filtered and the filtrate was evaporated to dryness in vacuo. The residue was taken up in benzene and chromatographed on silica-gel (60-fold). Some starting material was eluted with petroleumether/ether 2:1 and the dehydrogenation product with petroleumether/ether 2:1 and 1:1. The 16a,17a-isopropylidenedioxy-9B,10apregna-1,4-diene-3 ,20-dione was recrystallized from methylenechloride/diisopropylether melting point 172-174; [a] 28 :5 (dioxane) IR-, NMR- and mass-spectra are consistent with the structure.

(B) A suspension of 386 mg. (1 mmole) of 16.1,1711- isopropylidene dioxy 9,8,10u pregn 4 ene 3,20- one 295 mg. (1.3 mmoles) of 2,3-dichloro-5,6-dicyanobenzoquinone in 10 ml. of purified dioxane was refluxed for 6 hours. Within 20 minutes all material was in solution. After cooling, sodiumbicarbonate and a trace of water was added and the mixture refluxed for 3 minutes. The mixture was filtered, the filtrate was evaporated to dryness in vacuo, dissolved in benzene and chromatographed on silicagel as described above. The pure 16a, 17a-isopropylidenedioxy-9 3,IOa-pregna-1,4-diene,-3,20-dione was obtained pure after recrystallization from methylenechloride/diisopropylether, melting point 173174; identical in all respects 'with the material obtained above (A).

(10) 160a, 17a-isopropylidenedioxy-9B, 10ot-pregna-1,4,6-triene-3,20-dione (II) A solution of 384 mg. (1 mmole) of 16a-17ot-isopropylidenedioxy-9/3,l0a-pregna-4,6-diene-3,20-di0ne (I) and 295 mg. (1.3 mmoles) of 2,3-dichloro-5,6-dicyanobenzoquinone in 10 ml. of purified dioxane, containing 2% o. of hydrochloric acid was stirred at room temperature for 1 /2 hours. An excess of sodium carbonate and a trace of Water was added. The mixture was refluxed for 3 minutes, filtered and the filtrate was evaporated to dryness in vacuo. The residue was dissolved in benzene and chromatographed on silica gel (40-fold). The 16st, 17a-is0propylidenedioxy-913, loot-pregna-1,4,6-triene-3,20- dione' (II) was eluted with petroleumether/ether 1:1 and recrystallized from methylenechloride/diisopropylether, melting point 203; [a] =327 :5 (dioxane),

UV: x532? (e 221.5 m (12,600), 252 m, (9,660), 300.5 mg (13,080)

IR-, NMR- and mass-spectra are consistent with the structure.

EXAMPLE 11 2 g. of 16a,l7a-isopropylidene-dioxy-9/3,10a-pregn-4- ene,3,20-dione were dissolved in chloroform, which solution was mixed homogeneously with 194 g. of lactose. The mixture was dried at 40 C. during 1 hour. The mixture was wetted with a 10% aqueous solution of 2 g. of gelatine and subsequently ground through a 20 mesh sieve. The mixture was dried at 40 C. during 24 hours, whereupon the granules were ground through a 20 mesh sieve. The mixture was weighed and then had added to it proportional amounts of Talcum venetum and magnesium stearate in amounts of optimally 25 mg. and 2 mg. respectively. The resulting mixture was homogenised and worked to tablets of 225 mg. each.

EXAMPLE 12 Injection liquids of 16a,17a-isopropylidene-dioxy-9fi, 10u-pregna-4,6-diene-3,20-dione (active ingredient) were made as follows.

5.00 g. of the active ingredient were dissolved in 90 mls. of a solution of 2% w./v. benzylalcohol and 46 w./v. benzylbenzoate in ricinic oil at a temperature of 60 C. The solution was cooled to room temperature and replenished to 100 mls. with the ricinic oil solution aforesaid. The mixture was homogenised by stirring and filtrated. Ampoules and vials were filled with the filtrated solution, subsequently sealed and then sterilised by heat ing for one hour at 120.

What we claim is:

1. Compounds of the formula (llHzRtr /\o[3 :0 l --O\O/X1 E I "0 X2 4 E R3 wherein R is a moiety selected from the group consisting of 3-keto-4-dehydro, 3-keto-4,6-bisdehydro, 3-keto-1,4, 6-trisdehydro, 3-alkoxy-3,5-bisdehydro, and 3-acyloxy- 3,5-bisdehydro,

wherein said alkoxy radical contains from 1 to carbon atoms inclusive and said acyloxy radical is an aliphatic acyloxy group of 1 to 6 carbon atoms inclusive,

R is a member selected from the group consisting of hy (3:0 CH3 CH3 E 0 CH3 3. A compound of claim 1 corresponding to the formula:

r a. i=

3 a i O CHs I I 0:

4. A compound of claim 1 corresponding to the formula:

5. A compound of claim 1 corresponding to the formula:

I i l of claim 1 corresponding to the for- 6. A compound mula:

13 14 7. A compound of claim 1 corresponding to the for- 9. As a compound of claim 1, 6-Chl0rO-16u,l7oL-iSO- mula: propylidenedioXy-9p, 10a-pregn-4-ene-3,ZO-dione.

10. As a compound of claim 1, 6-Cl1101'0-16oc,17-1S0- propylidenedioxy-9 ,IOa-pregna-1,4,6-triene-3,20-dione.

11. As a compound of claim 1, 6-Ch10l'0-16oc,17a-l$0- propylidenedioxy-9fl-10a-pregna-1,4,6-triene-3,20-dione.

-----0 0H i 12. As a compound of dam 1, 6-fl110I0-16oc,170L-1S0- \CH propy1idenedioxy-9B-IOa-pregna-1,4-diene-3,20-dione. 5 13. As a compound of claim 1, 6-flu0ro-16u,17u-isopropylidenedioXy-9fi,10a-pregna-4-one-3,20-dione.

14. As a compound of claim 1, 6-flUO1'0-16a,17u-i50 Ha propylidenedioxy-9fl, 10a-pregna-4,6-cliene-3 ,20-dione.

H References Cited 81. A compound of claim 1 corresponding to the for- UNITED STATES PATENTS mu 3,134,770 5/1964 Fried 260-23955 5 3,174,971 3/1965 Krakower et al. 260-23955 I ELBERT L. ROBERTS, Primary Examiner on: L CH: i i 0/ CHa 0 2 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,523,943 (PHN 934B) Dated August 11, 1970 Inventr( ENGBERT HARMEN REERINK ET AL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, the formula in I (e) should read:

011 0 x O 3 0 \X Column 5, line 22, cancel "as" (first occurance) line 58, "means" should read meanings Column 6, line 25, "ampullosoporum" should read ampullosporum line 27, "curtesii" should read curtisii Column 7, line 71, "vacuuo" should read vacuo Column l4,line 4, "9" should read 9B line 3, "17" should read 17a Signed and sealed this 18th day of July 1972.

(SEAL) Attest:

EDWARD M.F'LETCHER,JR. ROBERT GOITSCHALK Attasting Officer Commissioner of Patents 

